Clutch for torque transmission between a shaft and a roller which is arranged coaxially around the shaft

ABSTRACT

The present invention relates to a clutch ( 20 ) for torque transmission between a shaft ( 2 ) and a roller ( 30 ) which is arranged coaxially around the shaft ( 2 ), comprising pneumatically actuable means for selectively interrupting and/or producing a force flow between the shaft ( 2 ) and roller ( 30 ), wherein the clutch ( 20 ) is arranged within the roller ( 30 ) coaxially between the shaft ( 2 ) and roller ( 30 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of German patent application 20 2006008 681.1, filed Jun. 1, 2006, herein incorporated by reference.

FIELD OF THE INVENTION

The invention relates to a clutch for transmitting torque between ashaft and a roller arranged coaxially around the shaft, comprisingpneumatically actuable means for the selective interruption and/orproduction of a force flow between the shaft and roller.

BACKGROUND OF THE INVENTION

The driving of rotatably mounted drums, cylinders or rollers ofstationary machines, such as, for example, paper machines, rotarymachines or the likes, generally takes place by driving a shaftextending coaxially to a roller, the shaft and roller being connected toone another by means of a clutch transmitting the drive torque.

Clutches of the type which are arranged coaxially between a shaft and aroller arranged coaxially to the shaft are particularly space-savinghere.

A clutch of this type for transmitting a torque between a spindle orshaft and a roller is known from German Patent Publication DE 26 50 692A1.

In order to be able to temporarily stop or drive individual shaftsand/or rollers of continuously driven machines, it is necessary toarrange a preferably remotely controllable clutch which can bedisengaged and/or engaged between the drive and the respective roller.

A clutch of this type should be as easy as possible to activate,substantially maintenance-free and operable with simple means. Moreover,it is desirable that there is no risk of an explosion, and no danger ofcontamination of the product produced by a respective machine from themeans for actuating the clutch, for example in the event of a defect. Onthe other hand, the means should be as easily available as possible.

A pneumatically actuable disc clutch for rope pulleys, belt pulleys orthe like to be driven and freely rotatably mounted on a drive shaft isknown from German Patent Publication DE 1 747 650 U1. To actuate theclutch, a pneumatic cylinder which is formed from a tube piece isprovided, the piston of which is formed by a disc arranged in the tube.The clutch is disengaged, upon an interruption of the compressed airsupply, by means of a spring against the restoring force of the piston.The clutch is arranged at the free end of the drive shaft, the pneumaticcylinder and the clutch discs having a larger diameter than the shaftand a drive shaft connected, for example, to a rope pulley. Thedisadvantage of this is that the known disc clutch projects both in theaxial and in the radial direction over the drive shaft and the outputshaft. Therefore, no mounting of the shafts is possible, for example, atthe end at which the disc clutch is arranged. In addition, installationspace is required as a result, which cannot be provided in a largenumber of machines. This makes the known disc clutch unusable formachines in which a two-sided mounting of the shaft and the rollerarranged thereon is required. Moreover, a complete restoring of theclutch discs by the springs against the restoring force of the pistoncannot be ensured so a high degree of wear of the clutch discs occurs asthey already have slippage between them when a minimum pressing force isfallen below and thus abrade one another.

SUMMARY OF THE INVENTION

An object of the invention is therefore to provide a clutch with theaforementioned advantageous properties, which moreover is simply andeconomically constructed and can be actuated as easily as possible andwithout a large outlay for wiring, and which can be used on machines inwhich a two-sided mounting of the shaft and roller is required.

The object is achieved in a clutch of the type mentioned at the outsetin that the clutch is completely arranged within the roller coaxiallybetween the shaft and roller.

The clutch according to the invention, compared to the prior art, hasthe advantage that, without needing additional installation space, itallows a selective interruption or production of a force flow between ashaft and a roller arranged coaxially with respect to the shaft and theshaft can moreover be mounted at the two ends. Thus, the clutchaccording to the invention can be used in machines in which highprecision is required when mounting shafts and rollers relative to oneanother by a two-sided mounting, for example in the case of papermachines, or else machines of the type in which the shafts and rollershave high masses because of their dimensions and therefore, likewise, atwo-sided mounting is required. Operation of the clutch according to theinvention moreover represents an easily available means which, forexample, in the event of a defect, does not pose a risk of explosion orendanger the quality of a product produced by a machine which isprovided with a clutch according to the invention, for example bysoiling.

The subject of the invention therefore provides a clutch which can beactuated by compressed air for selective interruption or production oftorque transmission between coaxially arranged shafts and rollers, whichis simply and economically constructed, can be actuated easily andwithout a large outlay for wiring, and can, in particular, be used inmachines, in which a two-sided mounting of the shaft and roller isnecessary.

An advantageous configuration of the invention provides that thepneumatically actuable means comprise a pneumatic cylinder arrangedcoaxially between the shaft and cylinder and rotatably mounted relativeto the shaft and the roller, comprising a clutch disc arranged on itsextendable end, which pneumatic cylinder acts with its piston on aclutch disc rotatably arranged relative to the piston andnon-rotationally connected to the shaft or roller, and presses it, onactuation of the clutch against a corresponding face non-rotationallyconnected to the roller or shaft, and/or lifts it therefrom.

The pneumatic cylinder preferably comprises a circular piston arrangedcoaxially between the shaft and roller. As a result, the shaft can beguided through the pneumatic cylinder, simultaneously achieving as largea piston face as possible.

So that the pneumatic cylinder does not co-rotate with the shaft orroller, it is conceivable to connect the pneumatic cylinder with itscover facing the end of the shaft to an abutment. The abutment may beconfigured as a plate with a central opening for guiding the shaftthrough, which can be connected to a component provided for mounting theshaft.

Another advantageous configuration of the invention provides that thepneumatic cylinder comprises a restoring spring, which, upon aninterruption of the compressed air supply, returns the piston of thepneumatic cylinder into a starting position. This ensures that theclutch disc, on non-actuation of the clutch, in other words when thereis an interruption of the compressed air supply to the pneumaticcylinder, is safely moved into the position which is then desired, andno further pressing force of the clutch disc against the correspondingface is produced by the piston of the pneumatic cylinder. This avoidsexcessive wear of the clutch disc, for example by rubbing on thecorresponding face.

An additional advantageous configuration of the invention provides thatthe pneumatically actuable means are only used to interrupt or produce aforce flow between the shaft and the roller, and spring-loaded means areprovided for the reverse process, in other words to produce or interruptthe force flow. As a result, the activation of the clutch issignificantly simplified, in particular it can be ensured that owing tothe spring-loaded means, in the event of a failure of the compressed airsupply, a preferably desired operating state of the clutch is produced,for example engaged or disengaged.

A particularly advantageous configuration of the invention provides thatthe spring-loaded means comprise one or more compression springspreferably arranged coaxially to a pneumatic cylinder, for example aspiral spring, disc spring or the like.

An additional, particularly advantageous configuration of the inventionprovides that the piston of the pneumatic cylinder, upon a supply ofcompressed air, lifts the clutch disc from the corresponding faceagainst the spring loading, the spring-loaded means, preferablyconfigured as a compression spring, pressing the clutch disc against thecorresponding face when the pneumatic cylinder is cut off from thecompressed air supply, in other words in the event of an interruption ofthe compressed air supply.

An advantageous configuration of the invention provides that the clutchdisc is non-rotationally connected to the roller, and the correspondingface is non-rotationally connected to the shaft.

Another advantageous configuration of the invention provides that thenon-rotational connection between the roller and clutch disc takes placeby means of grooves extending on the inside on the roller parallel tothe longitudinal axis thereof, as well as projections arranged on theclutch disc and engaging in the grooves. The clutch disc can belongitudinally displaced relative to the roller owing to the use ofgrooves and projections. It is likewise conceivable to provide a carrierpressed in the roller, which carrier has the grooves provided to entrainthe clutch disc, and/or projections. This simplifies the productiondecisively as handling the relatively large roller is laborious.

A particularly advantageous configuration of the invention provides thatthe corresponding face comprises a face extending normal to thelongitudinal axis of the shaft, of a hub arranged on the inside in theroller and non-rotationally connected to the shaft. A friction lining ispreferably arranged on the corresponding face. The friction lining ispreferably replaceable.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of a longitudinal section through a clutchaccording to the invention arranged coaxially between a shaft and aroller,

FIG. 2 shows a perspective view of the clutch according to the inventionfrom FIG. 1 without the shaft and roller,

FIG. 3 shows a side view of the clutch according to the invention fromFIG. 1, and

FIG. 4 shows a perspective detailed view of a clutch disc of a clutchaccording to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A clutch 20 according to the invention shown in FIG. 1 to 3 is arrangedinside a roller 30 coaxially between the roller 30 and a shaft 2. Theclutch 20 substantially comprises a pneumatic cylinder 3 arrangedcoaxially between the shaft 2 and roller 30 and rotatably mountedrelative to the shaft 2 and roller 30, comprising a circular piston 11.The piston 11 acts on a clutch disc 8, which is non-rotationallyconnected to the roller 30. A hub 1 non-rotationally connected to theshaft 2 has a face 13 corresponding to the clutch disc 8. Compressionsprings 9 press the clutch disc 8 against the corresponding face 13. Thepiston 11 of the pneumatic cylinder 3, upon a supply of compressed air,lifts the clutch disc 8 from the corresponding face 13 and interruptsthe force flow between the shaft 2 and roller 30. The roller 30 thenstands still even if the shaft 2 continues to be driven. The clutch 20is screwed to the hub 1 on the shaft 2. Located in the clutch 20 is anannular pneumatic cylinder 3 which is decoupled by a ball bearing 4 fromthe rotating parts of the clutch 20. The pneumatic cylinder 3 is screwedto a cover 5 and an abutment 6 and is thereby held tight.

If the pneumatic cylinder 3 is pressureless, the clutch 20 is engagedand the force flow goes via the shaft 2, the corresponding face 13 ofthe hub 1 provided with a friction lining 7 onto the clutch disc 8,which is pressed by compression springs 9. For disengagement, compressedair is supplied to the pneumatic cylinder 3. Compressed air isintroduced, for example, into the pneumatic cylinder 3 via an external3/2-way valve through an air inlet 16. As a result, the piston 11 of thepneumatic cylinder 3 is extended and presses the clutch disc 8 away fromthe friction lining 7 of the corresponding face 13. As a result, theforce flow is interrupted and the roller 30 stands still.

The pneumatic cylinder 3 is preferably single-acting and the piston 11is compressed by disc springs 12. The entraining force, corresponding tothe torque which can be transmitted by the clutch 20, may be varied bythe strength of the compression springs 9.

The clutch disc 8 has, at its periphery, four segments 14 (FIG. 4),which engage in corresponding recesses 15 of the carrier 10 (FIG. 2) andthus produce the force flow to the roller.

A roller designed, for example, as a winding cylinder, friction rolleror the like can be coupled to or decoupled from a continuously rotatingshaft by the pneumatic clutch according to the invention.

The invention can be industrially applied in particular in the area ofthe production of clutches for torque transmission between coaxiallyarranged shafts and rollers.

LIST OF REFERENCE NUMERALS

-   1 hub-   2 shaft-   3 pneumatic cylinder-   4 ball bearing-   5 cover-   6 abutment-   7 friction lining-   8 clutch disc-   9 compression spring-   10 carrier-   11 piston-   12 disc spring-   13 corresponding face-   14 segment-   15 recess-   16 air inlet-   20 clutch-   30 roller

What is claimed is:
 1. Clutch (20) for transmitting torque between ashaft (2) and a roller (30) arranged coaxially around the shaft (2),comprising pneumatically actuatable means for selectively interruptingor producing a force flow between the shaft (2) and roller (30),characterized in that the clutch (20) is arranged inside the roller (30)coaxially between the shaft (2) and roller (30), and wherein thepneumatically actuatable means comprises a pneumatic cylinder (3) with apiston (11) movable therein, the pneumatic cylinder being rotatablymounted relative to the shaft (2) and the roller (30) with the piston(11) acting on a rotatably arranged clutch disc (8) non-rotationallyconnected to the shaft (2) or roller (30) for pressing said clutch disc,on actuation of the clutch, against a corresponding face (13)non-rotationally connected to the roller (30) or shaft (2), oralternatively for lifting said clutch disk from said corresponding face(13).
 2. Clutch according to claim 1, characterized in that thepneumatic cylinder (3) comprises a circular piston arranged coaxiallybetween the shaft (2) and roller (30).
 3. Clutch according to claim 1 or2, characterized in that the pneumatic cylinder (3) comprises arestoring spring (12), which, upon an interruption of the compressed airsupply, returns the piston (11) of the pneumatic cylinder (3) into astarting position.
 4. Clutch according to claim 1, characterized in thatthe pneumatically actuable means are operable only to alternativelyinterrupt or produce a force flow between the shaft (2) and the roller(30), and spring-loaded means are provided to act in opposition to thepneumatically actuable means.
 5. Clutch according to claim 4,characterized in that the spring-loaded means comprise a compressionspring (9).
 6. Clutch according to either of claim 4 or 5, characterizedin that the piston (11) of the pneumatic cylinder (3), upon a supply ofcompressed air, lifts the clutch disc (8) from the corresponding face(13) against the spring loading, wherein the spring-loaded means (9)presses the clutch disc (8) against the corresponding face (13) when thesupply of compressed air is interrupted.
 7. Clutch according to claim 1,characterized in that the clutch disc (8) is non-rotationally connectedto the roller (30) and the corresponding face (13) is non-rotationallyconnected to the shaft.
 8. Clutch according to claim 7, characterized inthat the non-rotational connection between the roller (30) and clutchdisc (8) takes place by means of grooves (15) extending on the inside onthe roller (30) parallel to the longitudinal axis thereof, andprojections (14) arranged on the clutch disc (8) and engaging in thegrooves (15).
 9. Clutch according to claim 7, characterized in that thenon-rotational connection between the roller (30) and clutch disc (8) isformed by means of a carrier (10), which can be arranged in the rollerand has grooves (15) extending parallel to the longitudinal axis of theroller (30), as well as projections (14) arranged on the clutch disc (8)and engaging in the grooves (15) of the carrier.
 10. Clutch according toclaim 1, characterized in that the corresponding face comprises a face(13) extending normally to the longitudinal axis of the shaft (2) of ahub (1) arranged on the inside in the roller (30) and non-rotationallyconnected to the shaft (2).